- Location
- Letchworth Garden City, Hertfordshire
- Main postcode district
- SG6
- Nearby (straight line)
- Hitchin (3 miles), Stevenage (5 miles) and Biggleswade (8 miles)
- Survey and quote
- Free, with a fixed written quote
Dock traffic lights are red and green signals mounted outside and inside a loading bay to tell the driver and dock staff when it is safe to move or load. Interlocks are control links that stop equipment operating out of sequence, for example preventing the door opening until the trailer is restrained, or the leveller operating until the door is fully open.
Is this right for your site in Letchworth Garden City?
Whether your unit in Letchworth Garden City has one dock or twenty, the survey looks at each bay's existing controls before we quote a fixed price in writing. Food and chilled operations around Letchworth Garden City with inflatable shelters often add interlocks so the shelter only inflates once a trailer is docked and restrained.
Older docks in Letchworth Garden City with separate door and leveller controls can be brought into a proper sequence by adding interlocks that stop equipment working out of order.
It starts with a free site survey in Letchworth Garden City, where we measure the openings, check the dock and talk through how the bay is used. You then receive a fixed written quote. Once you accept, we manage the job: specialist installation engineers carry out the work under our management, planned around your deliveries, and out-of-hours working can be arranged. At handover we test everything with you and leave the documentation.
How much do dock traffic lights and interlocks cost?
Dock traffic lights and interlocks typically cost £650 to £3,400 per bay, supplied and fitted, excluding VAT. A pair of manually switched LED signals sits at the lower end, while a full interlock panel linking door, leveller, restraint and shelter sits towards the top.
What moves the price:
- Level of control: standalone lights, door-linked lights or a full interlocked sequence.
- Existing control panels: modern door and leveller panels often accept interlocks directly; older panels may need replacing with a combined bay panel.
- Sensors: door position switches, trailer presence sensors and restraint signals each add parts and wiring.
- Cable runs: distances between lights, panels and the power supply.
- Number of bays and timing: repeat bays reduce the cost per bay, while out-of-hours working adds to it.
These are guide budgets. After a free site survey we send a written quote, and that quote is the fixed price. VAT is added at the standard rate.
What happens on site when traffic lights and interlocks are fitted?
Fitting lights and interlocks is mainly electrical work, and each bay is out of use while its controls are connected and tested. Working bay by bay keeps the rest of the dock running.
- Fix the signals: the outside light is mounted on brackets at a height drivers can see, and the inside light beside the door.
- Run the cables: wiring is run in conduit or trunking between lights, sensors and control panels.
- Isolate and connect: the door and leveller supplies are isolated and locked off while the interlock wiring is connected, or a new bay panel is fitted.
- Test every sequence: each interlock is tested, including what happens if a step is attempted out of order.
- Brief staff: dock staff are shown the new sequence, and signs are fitted for drivers.
It helps if you can provide any electrical drawings for the dock, access to the distribution board, a person who can authorise isolations and an agreed order for releasing bays.
The same published guide range applies across England; access, out-of-hours working and site conditions are confirmed at the free survey.
Survey checklist for your dock
- Working hours, shift patterns and windows for out-of-hours work
- Control positions, isolators and any existing interlocks
- Asbestos register and any other site hazard information
- Power supply at each bay, including three-phase availability
- Yard gradient and the slope of the approach to the dock
- Bumper position and wear or damage on the dock face
Options to discuss
Standalone LED traffic lights
A red and green pair for each bay, one outside for the driver and one inside for dock staff, switched manually from a control beside the door.
Full bay interlock panel
A single control panel that runs the door, leveller, restraint and shelter in the correct sequence, with indicators showing which step is active or blocked.
Planning, building control and safety law in England
Workplace safety in England is regulated by HSE. For a loading bay in Letchworth Garden City, that means doors meeting regulation 18 of the Workplace (Health, Safety and Welfare) Regulations 1992, equipment maintained under PUWER and suitable safeguards against vehicles driving away too early. We check what applies at survey and design the bay accordingly.
Questions about dock traffic lights and interlocks in Letchworth Garden City
Which building and safety rules apply to a site in Letchworth Garden City?
It depends on which UK nation the site is in. England and Wales use Building Regulations approval, Scotland uses building warrants and Northern Ireland uses building control approval from the council. Workplace safety is regulated by HSE in Great Britain and HSENI in Northern Ireland, and energy rules differ between nations. For your site in Letchworth Garden City, we check what applies at survey and design to it.
Is the site survey in Letchworth Garden City free?
Yes. For new installations, replacements, upgrades, conversions and complete bays, the site survey and written quote are free and come with no obligation. The survey lets us measure the openings, check the dock and structure, and understand how the bay is used, so the quote reflects your site. Repair and servicing visits are different: they are chargeable, with the price agreed before anyone attends.
Can you work outside our normal operating hours in Letchworth Garden City?
Yes, by arrangement. Evening, night and weekend working can be planned so the installation causes as little disruption as possible to your loading schedule. Out-of-hours work can affect the price, so mention it at the survey and we will include it in the written quote. The agreed times are confirmed in the programme before the job starts.
Can you add lights and interlocks across a whole dock in one project?
Yes. A whole-dock project is usually phased bay by bay so most doors stay in use, and every bay ends up on the same control standard. That consistency makes training easier for staff and drivers, and it simplifies servicing because every bay behaves in the same way.
Can interlocks be fitted to a manual loading bay door?
Yes. A door position switch fitted to a manual door can confirm when it is fully open or fully closed. That signal lets the traffic lights change automatically and stops the leveller being raised until the door is out of the way.
Dock traffic lights and interlocks near Letchworth Garden City
We also cover towns near Letchworth Garden City, including Hitchin (3 miles), Stevenage (5 miles) and Biggleswade (8 miles). Each has its own page with the same services and process.
Other loading bay services in Letchworth Garden City
Full guide to dock traffic lights and interlocks · Everything we do in Letchworth Garden City
Request a quote for your loading bay in Letchworth Garden City, attaching photos of the dock, the equipment and any damage.